package stepcas import ( "context" "crypto/x509" "net/url" "time" "github.com/pkg/errors" "github.com/smallstep/certificates/api" "github.com/smallstep/certificates/ca" "github.com/smallstep/certificates/cas/apiv1" ) func init() { apiv1.Register(apiv1.StepCAS, func(ctx context.Context, opts apiv1.Options) (apiv1.CertificateAuthorityService, error) { return New(ctx, opts) }) } // StepCAS implements the cas.CertificateAuthorityService interface using // another step-ca instance. type StepCAS struct { x5c *x5cIssuer client *ca.Client fingerprint string } // New creates a new CertificateAuthorityService implementation using another // step-ca instance. func New(ctx context.Context, opts apiv1.Options) (*StepCAS, error) { switch { case opts.CertificateAuthority == "": return nil, errors.New("stepCAS 'certificateAuthority' cannot be empty") case opts.CertificateAuthorityFingerprint == "": return nil, errors.New("stepCAS 'certificateAuthorityFingerprint' cannot be empty") } caURL, err := url.Parse(opts.CertificateAuthority) if err != nil { return nil, errors.Wrap(err, "stepCAS `certificateAuthority` is not valid") } if err := validateCertificateIssuer(opts.CertificateIssuer); err != nil { return nil, err } // Create client. client, err := ca.NewClient(opts.CertificateAuthority, ca.WithRootSHA256(opts.CertificateAuthorityFingerprint)) if err != nil { return nil, err } // X5C is the only one supported at the moment. x5c, err := newX5CIssuer(caURL, opts.CertificateIssuer) if err != nil { return nil, err } return &StepCAS{ x5c: x5c, client: client, fingerprint: opts.CertificateAuthorityFingerprint, }, nil } func (s *StepCAS) CreateCertificate(req *apiv1.CreateCertificateRequest) (*apiv1.CreateCertificateResponse, error) { switch { case req.CSR == nil: return nil, errors.New("createCertificateRequest `template` cannot be nil") case req.Lifetime == 0: return nil, errors.New("createCertificateRequest `lifetime` cannot be 0") } cert, chain, err := s.createCertificate(req.CSR, req.Lifetime) if err != nil { return nil, err } return &apiv1.CreateCertificateResponse{ Certificate: cert, CertificateChain: chain, }, nil } func (s *StepCAS) RenewCertificate(req *apiv1.RenewCertificateRequest) (*apiv1.RenewCertificateResponse, error) { switch { case req.CSR == nil: return nil, errors.New("renewCertificateRequest `template` cannot be nil") case req.Lifetime == 0: return nil, errors.New("renewCertificateRequest `lifetime` cannot be 0") } cert, chain, err := s.createCertificate(req.CSR, req.Lifetime) if err != nil { return nil, err } return &apiv1.RenewCertificateResponse{ Certificate: cert, CertificateChain: chain, }, nil } func (s *StepCAS) RevokeCertificate(req *apiv1.RevokeCertificateRequest) (*apiv1.RevokeCertificateResponse, error) { switch { case req.SerialNumber == "" && req.Certificate == nil: return nil, errors.New("revokeCertificateRequest `serialNumber` or `certificate` are required") } serialNumber := req.SerialNumber if req.Certificate != nil { serialNumber = req.Certificate.SerialNumber.String() } token, err := s.revokeToken(serialNumber) if err != nil { return nil, err } _, err = s.client.Revoke(&api.RevokeRequest{ Serial: serialNumber, ReasonCode: req.ReasonCode, Reason: req.Reason, OTT: token, Passive: req.PassiveOnly, }, nil) if err != nil { return nil, err } return &apiv1.RevokeCertificateResponse{ Certificate: req.Certificate, CertificateChain: nil, }, nil } // GetCertificateAuthority returns the root certificate of the certificate // authority using the configured fingerprint. func (s *StepCAS) GetCertificateAuthority(req *apiv1.GetCertificateAuthorityRequest) (*apiv1.GetCertificateAuthorityResponse, error) { resp, err := s.client.Root(s.fingerprint) if err != nil { return nil, err } return &apiv1.GetCertificateAuthorityResponse{ RootCertificate: resp.RootPEM.Certificate, }, nil } func (s *StepCAS) createCertificate(cr *x509.CertificateRequest, lifetime time.Duration) (*x509.Certificate, []*x509.Certificate, error) { sans := make([]string, 0, len(cr.DNSNames)+len(cr.EmailAddresses)+len(cr.IPAddresses)+len(cr.URIs)) for _, s := range cr.DNSNames { sans = append(sans, s) } for _, s := range cr.EmailAddresses { sans = append(sans, s) } for _, ip := range cr.IPAddresses { sans = append(sans, ip.String()) } for _, u := range cr.URIs { sans = append(sans, u.String()) } commonName := cr.Subject.CommonName if commonName == "" && len(sans) > 0 { commonName = sans[0] } token, err := s.signToken(commonName, sans) if err != nil { return nil, nil, err } resp, err := s.client.Sign(&api.SignRequest{ CsrPEM: api.CertificateRequest{CertificateRequest: cr}, OTT: token, NotAfter: s.lifetime(lifetime), }) if err != nil { return nil, nil, err } var chain []*x509.Certificate cert := resp.CertChainPEM[0].Certificate for _, c := range resp.CertChainPEM[1:] { chain = append(chain, c.Certificate) } return cert, chain, nil } func (s *StepCAS) signToken(subject string, sans []string) (string, error) { if s.x5c != nil { return s.x5c.SignToken(subject, sans) } return "", errors.New("stepCAS does not have any provisioner configured") } func (s *StepCAS) revokeToken(subject string) (string, error) { if s.x5c != nil { return s.x5c.RevokeToken(subject) } return "", errors.New("stepCAS does not have any provisioner configured") } func (s *StepCAS) lifetime(d time.Duration) api.TimeDuration { if s.x5c != nil { d = s.x5c.Lifetime(d) } var td api.TimeDuration td.SetDuration(d) return td }